XFormsDB - An XForms-Based Framework for Simplifying Web Application Development

WWW:n luonne muuttuu jatkuvasti vastatakseen paremmin käyttäjien kasvavia tarpeita. Vaikka tämä kehitys kohti hyödyllisempiä vuorovaikutteisia palveluita ja sovelluksia on parantanut WWW:n käyttö- ja käyttäjäkokemusta, niin se on myös samalla tehnyt WWW-sovellusten kehittämisestä paljon monimutkaisempaa. Tämän työn päätavoitteena oli tutkia, miten WWW-sovellusten kehittämistä voitaisiin helpottaa deklaratiivisen ohjelmoinnin keinoin. Työssä esitetään laajennus, jonka avulla yleisimmät palvelinpään toiminnallisuudet voidaan saumattomasti liittää osaksi XForms-merkintäkieltä. Myös laajennuksen käyttökelpoisuus ja mahdollisuudet validoidaan prototyyppitoteutuksen, nimeltään XFormsDB-ohjelmistokehys, ja kahden WWW-esimerkkisovelluksen avulla. Tulokset osoittavat, että XFormsDB-ohjelmistokehyksen avulla voidaan kirjoittaa hyödyllisiä, erittäin vuorovaikutteisia monen käyttäjän WWW-sovelluksia nopeasti ja helposti vain yhtä dokumenttia ja yhtä ohjelmointimallia käyttäen.The nature of the World Wide Web is constantly changing to meet the increasing demands of its users. While this trend towards more useful interactive services and applications has improved the utility and the user experience of the Web, it has also made the development of Web applications much more complex. The main objective of this Thesis was to study how Web application development could be simplified by means of declarative programming. An extension that seamlessly integrates common server-side functionalities to the XForms markup language is proposed and its feasibility and capabilities are validated with a proof-of-concept implementation, called the XFormsDB framework, and two sample Web applications. The results show that useful, highly interactive multi-user Web applications can be authored quickly and easily in a single document and under a single programming model using the XFormsDB framework

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

The DS-Pnet modeling formalism for cyber-physical system development

This work presents the DS-Pnet modeling formalism (Dataflow, Signals and Petri nets), designed for the development of cyber-physical systems, combining the characteristics of Petri nets and dataflows to support the modeling of mixed systems containing both reactive parts and data processing operations. Inheriting the features of the parent IOPT Petri net class, including an external interface composed of input and output signals and events, the addition of dataflow operations brings enhanced modeling capabilities to specify mathematical data transformations and graphically express the dependencies between signals. Data-centric systems, that do not require reactive controllers, are designed using pure dataflow models. Component based model composition enables reusing existing components, create libraries of previously tested components and hierarchically decompose complex systems into smaller sub-systems. A precise execution semantics was defined, considering the relationship between dataflow and Petri net nodes, providing an abstraction to define the interface between reactive controllers and input and output signals, including analog sensors and actuators. The new formalism is supported by the IOPT-Flow Web based tool framework, offering tools to design and edit models, simulate model execution on the Web browser, plus model-checking and software/hardware automatic code generation tools to implement controllers running on embedded devices (C,VHDL and JavaScript). A new communication protocol was created to permit the automatic implementation of distributed cyber-physical systems composed of networks of remote components communicating over the Internet. The editor tool connects directly to remote embedded devices running DS-Pnet models and may import remote components into new models, contributing to simplify the creation of distributed cyber-physical applications, where the communication between distributed components is specified just by drawing arcs. Several application examples were designed to validate the proposed formalism and the associated framework, ranging from hardware solutions, industrial applications to distributed software applications

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks